1. Field of Invention
The present invention relates to self-latching clamps for power lines and the like.
2. Description of the Prior Art
There are a number of situations when it has been necessary to connect protective grounding equipment to electrical power distribution lines. The grounding equipment was mounted at an end of an elongate insulative rod, known in the industry as a "hot stick", and raised for connection onto the power line. Typically, the grounding equipment had a stirrup or notch which was placed over the power line. The grounding equipment also included a rotatable threaded rod or bolt having an eyelet at a lower end and a gripping jaw at an upper end. The bolt and eyelet were rigidly held in a hollow upper portion of the hot stick as the grounding equipment was raised to the power line and the stirrup placed on the power line. The bolt and eyelet were then released from the hot stick so that a hook at an upper end of the hot stick could engage the eyelet. This engagement was by nature a relatively loose one. The hot stick could then be rotated by the line crew, moving the bolt inwardly, as long as the hook engagement with the eyelet was maintained. Rotation was continued until the gripping jaw firmly held the power line in place in the stirrup.
So long as the power line was in a substantially horizontal plane and the line crew on the ground below, these apparatus were generally adequate. There were several situations, however, where problems were presented. For example, there are a number of types of electrical power distribution equipment from which the power lines extend in directions other than horizontally. Examples are breakers and transformers where it was not unusual to have the power line at angles of 45.degree. or more from the horizontal. With these and other equipment, a power line could also be nearly vertical.
With power lines in non-horizontal planes, the grounding equipment due to its own weight tended to slide down the power line or fall off the line. It was also a difficult task to rotate the threaded rod which was only loosely engaged at its eyelet with the hook on the hot stick. Another problem situation occurred with the line crew member was on a support pole working on a generally horizontal line at about the same elevation. Again, manipulation and rotation of the threaded rod was a cumbersome and awkward task.